Display "harvesting" 1. - Power Up

As I have nothing more to do with the logic analyzer now (there is national holiday here in Hungary and I'll have other things to do on the next week, I've no chance to get a new quieter fan and work with it till 2nd November), I picked something waiting to me from the drawer.

I've around fifty of this. I've no PBX for this anymore, so it is useless except for some parts "harvesting".
First of all I disassembled one, and realized, that the only part can be useful is the display unit. I need to reverse engineer a little bit to find out, how can I drive it.
I was looking around but nothing found on the internet. No information, no service manual, no schematic design. In addition the display driver chip is the regular silicon mounted on the board type:

(how I hate these)
So, the first thing, to power it up somehow, because without the PBX, I not even know what kind of power source is needed. It was obvious for the first look that the main board contains a switching regulator:

I looked to the regulator IC, it wasn't familiar to me:

But I assumed that -5 mark means 5V. If I connect a little bit more than 5V to the +- pins of the rectifier bridge:

It will bring the unit alive. And around 8V:

The unit started.
To be continued...

Multimeterles 3. - Engineering Masterpiece

A multimeter arrived today. Now I've four of them, what is close to I'm expected on the beginning.
I wasn't aware of what is this thing when I was bidding on it on the ebay. But after it arrived I'm absolutely sure it worth every dime I payed for it. If I where in the place of Dave Jones, I would create a long YouTube teardown video with many "awesome" and "beauty" in it. But I'm not, so photos and some text coming.
After a such long introduction let see, what we talking about.
A Fluke 8500A 6.5 digit bench multimeter.

As you see this is not a unit manufactured today. To be honest, I don't know the exact manufacturing date, but the manual I found on the internet was created in 1977. This give us the hint that the unit is roughly 35 years old. 1977 you know, the year of Star Wars. :-)
It is coming from the ages when the products of the US companies was manufactured in the U.S.A.

The unit is heavy. It is around 10Kg. And in addition it was packed and sealed in the way in the box like it would survive even an atomic war.
When I switched on, it started immediately. I made some measurements against my references, together with my HP multimeter.
Voltage:

It is slightly off, so it will need some calibration if I'll use as a reference as I planed.
Resistance:

It looks on spot. By the way it would be nice to use the 4-wire resistance measurement, but I should buy some proper test leads (Kelvin clips) for it.

After the testing I opened the box (This was the second time. The first time was in the office with my colleague).

 I was shocked. Never ever seen such order in any equipment (specially in something what is old like this). This looks like an engineering masterpiece.
Every single board is enclosed in a separate plastic cover. Every single board's plastic cover has a foldable door on the top of it, allowing access to calibration handles:

And finally a card with cover opened:

I'm really happy, that I'm the owner of this equipment now on.

USB supply - teardown

I'm sure you know that small slim power supplies what you connect to the mains and it has a USB on the top. That ones, what supplied for the iPhone.
I broke one of the mains legs.
I took it apart. Not the one supplied for the iPhone but a similar one, so there is no warranty that it is the same inside.
Here it is:

That's all.
The key component is a an ATS1636 named chip. It is manufactured by the "well known" ArtChip. Thay have a website. It is located on the artchipsemi.com address. The content is: 503 Service Unavailable.
I found a datasheet also:
http://www.szzcchina.com/cn/pdf%5CCH-ATS1636-V1p1.pdf

The chip according to the datasheet - because my Chinese is sooo good :-D (google translate):

"ATS1636 is suitable for low-cost, high-precision constant current and voltage requirements
(CC / CV) applications. Constant current loop without optocouplers, TL431 and complement
Compensation circuitry integrated 700V power MOSFET, reducing system cost.
ATS1636 meet the output voltage of ± 5% production accuracy. Pole
Low starting current, accurate detection can easily meet EPA2.0 bottom
Energy efficiency requirements. Output cable voltage compensation can be based on customer
The required adjustment, greatly facilitate the customer on the system design.
ATS1636 also integrates several protection features: undervoltage lockout, the former
Edge blanking, overvoltage protection, overcurrent protection, open loop protection, lose
Short circuit protection, which greatly increases the stability of the system. ATS1636
SOP-8 package is provided, ATS1636S for SOP-7 package."

I found a schematic diagram what mostly covers the thing what I have:
http://detail.1688.com/offer/1173450146.html

Fotek SSR-40DD Teardown

I tear apart the SSR producing 4V voltage drop. Removed most of the rubber and plastic crap inside.
Here is the result:

 

The key components:

• Motorola H11D1 optocoupler
• NEC 2SA1009 BJT (This is mostly an assumption, because it only have a A1009 sign on it)
• ST BUF420A BJT

A silent note: using a 30A BJT in a 40A rated equipment maybe not a good idea.